anaoshak

Q: "we couldn't create a new partition" 8.1 installation screen, iMac 5k

Well, here we are again.

 

I'm using an iMac 5k with a fusion drive. I'm trying to install Windows 8.1 and I'm getting the dreaded "we couldn't create a new partition" error during the windows installation screen. I also tried the format option within the windows installation partition screen. I ran into the issue before and instead used an Windows Enterprise ISO without any problems. Well that expired and now I'm back to using 8.1 Professional with a valid key. I also used a valid ISO retrieved from Windows. I didn't do anything to interrupt the Bootcamp assistant process. It wouldn't through the EFI drive. Can someone help me? Also can someone answer why this issue is prevalent through the iMac 5ks?

 

I'm using a USB 2.0 drive. Nothing else is plugged in.

 

 

/dev/disk0

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *121.3 GB   disk0

   1:                        EFI EFI                     209.7 MB   disk0s1

   2:          Apple_CoreStorage                         121.0 GB   disk0s2

   3:                 Apple_Boot Boot OS X               134.2 MB   disk0s3

/dev/disk1

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *1.0 TB     disk1

   1:                        EFI EFI                     209.7 MB   disk1s1

   2:          Apple_CoreStorage                         878.9 GB   disk1s2

   3:                 Apple_Boot Recovery HD             650.0 MB   disk1s3

   4:       Microsoft Basic Data                         120.5 GB   disk1s4

/dev/disk2

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:                  Apple_HFS Macintosh HD           *994.0 GB   disk2

                                 Logical Volume on disk0s2, disk1s2

                                 51129D2B-BB20-4415-9620-8517A8EC8ADC

                                 Unencrypted Fusion Drive

/dev/disk3

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:     FDisk_partition_scheme                        *8.0 GB     disk3

   1:                 DOS_FAT_32 WININSTALL              8.0 GB     disk3s1

Mac-ac87a3100dd4:~ arashsahba$ diskutil cs list

CoreStorage logical volume groups (1 found)

|

+-- Logical Volume Group 663F07EF-1F60-4CDB-AA72-5D3EA183E579

    =========================================================

    Name:         Internal Drive

    Status:       Online

    Size:         999855611904 B (999.9 GB)

    Free Space:   376832 B (376.8 KB)

    |

    +-< Physical Volume EC85191A-14F7-4871-AB96-24D19B592A6D

    |   ----------------------------------------------------

    |   Index:    0

    |   Disk:     disk0s2

    |   Status:   Online

    |   Size:     120988852224 B (121.0 GB)

    |

    +-< Physical Volume B46EAAAC-84A7-46E5-8375-E94692C4A837

    |   ----------------------------------------------------

    |   Index:    1

    |   Disk:     disk1s2

    |   Status:   Online

    |   Size:     878866759680 B (878.9 GB)

    |

    +-> Logical Volume Family B176540C-DB00-4534-B7DB-F35881AB28E6

        ----------------------------------------------------------

        Encryption Status:       Unlocked

        Encryption Type:         None

        Conversion Status:       NoConversion

        Conversion Direction:    -none-

        Has Encrypted Extents:   No

        Fully Secure:            No

        Passphrase Required:     No

        |

        +-> Logical Volume 51129D2B-BB20-4415-9620-8517A8EC8ADC

            ---------------------------------------------------

            Disk:                  disk2

            Status:                Online

            Size (Total):          993999978496 B (994.0 GB)

            Conversion Progress:   -none-

            Revertible:            No

            LV Name:               Macintosh HD

            Volume Name:           Macintosh HD

            Content Hint:          Apple_HFS

iMac (Retina 5K, 27-inch, Late 2014), OS X Yosemite (10.10.1), null

Posted on May 9, 2015 5:04 AM

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Q: "we couldn't create a new partition" 8.1 installation screen, iMac 5k

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  • by Loner T,

    Loner T Loner T May 9, 2015 5:49 AM in response to anaoshak
    Level 7 (24,115 points)
    Safari
    May 9, 2015 5:49 AM in response to anaoshak

    Can you post the output of

     

    sudo fdisk /dev/disk1

  • by anaoshak,

    anaoshak anaoshak May 9, 2015 12:50 PM in response to Loner T
    Level 1 (6 points)
    Windows Software
    May 9, 2015 12:50 PM in response to Loner T

    Disk: /dev/disk1 geometry: 121601/255/63 [1953525168 sectors]

    Signature: 0xAA55

             Starting       Ending

    #: id  cyl  hd sec -  cyl  hd sec [     start -       size]

    ------------------------------------------------------------------------

    1: EE 1023 254  63 - 1023 254  63 [         1 - 1953525167] <Unknown ID>

    2: 00    0   0   0 -    0   0   0 [         0 -          0] unused     

    3: 00    0   0   0 -    0   0   0 [         0 -          0] unused     

    4: 00    0   0   0 -    0   0   0 [         0 -          0] unused

  • by Loner T,

    Loner T Loner T May 9, 2015 1:05 PM in response to anaoshak
    Level 7 (24,115 points)
    Safari
    May 9, 2015 1:05 PM in response to anaoshak

    Can you look at Re: Windows 8.1 install on iMac with fusion drive, GPT partition error and and the steps with Gdisk and try Bootcamp installation?

  • by anaoshak,

    anaoshak anaoshak May 9, 2015 1:28 PM in response to Loner T
    Level 1 (6 points)
    Windows Software
    May 9, 2015 1:28 PM in response to Loner T

    I did the steps you mentioned. Now in regards to the bootcamp installation, do you want me to boot from EFI and head straight to the windows installation or start bootcamp assistant again  where it removes the partition, adds one, then installs windows?

     

    Thanks

  • by Loner T,

    Loner T Loner T May 9, 2015 1:32 PM in response to anaoshak
    Level 7 (24,115 points)
    Safari
    May 9, 2015 1:32 PM in response to anaoshak

    Do not use EFI boot, it will give you an error. Do not use BCA and start over again either. Use the USB you already have, and it should also have a Windows (not EFI Boot). Please use that. This is now a legacy BIOS boot installation.

  • by anaoshak,

    anaoshak anaoshak May 9, 2015 1:33 PM in response to Loner T
    Level 1 (6 points)
    Windows Software
    May 9, 2015 1:33 PM in response to Loner T

    So should I just restart my mac, hold option, then select Windows not EFI?

  • by Loner T,

    Loner T Loner T May 9, 2015 1:36 PM in response to anaoshak
    Level 7 (24,115 points)
    Safari
    May 9, 2015 1:36 PM in response to anaoshak

    Yes.

  • by anaoshak,

    anaoshak anaoshak May 11, 2015 4:26 PM in response to Loner T
    Level 1 (6 points)
    Windows Software
    May 11, 2015 4:26 PM in response to Loner T

    Your solution worked! Thank you so much. Do you mind explaining to me what's happening? I feel like I followed the steps correction, so what exactly is at fault? What exactly is the different between this installation and EFI?

     

    Thanks again!

  • by Loner T,

    Loner T Loner T May 11, 2015 4:38 PM in response to anaoshak
    Level 7 (24,115 points)
    Safari
    May 11, 2015 4:38 PM in response to anaoshak

    EFI installation uses a GPT partition style disk, while the current method uses the older BIOS method. The BIOS method has some limitations. For example, you cannot resize or repartition your disk any further. EFI method is a bit faster during boots, compared to BIOS, which is an emulation layer on top of EFI layer.

     

    Unified Extensible Firmware Interface - U(EFI) is an Intel standard which standardizes the interface between firmware and hardware. It also allows support for better features, that BIOS does not support.

  • by anaoshak,

    anaoshak anaoshak May 12, 2015 5:08 AM in response to Loner T
    Level 1 (6 points)
    Windows Software
    May 12, 2015 5:08 AM in response to Loner T

    Just curious what went wrong? Why can't I use EFI? Is this mostly because of the fusion drive? Will I be able to in the future? So I'm not able to resize / repartition. Am I still able to delete the bootcamp partition with ease and add it to OS X? I noticed my bootcamp is pretty slow to OSX.

  • by Loner T,

    Loner T Loner T May 12, 2015 5:33 AM in response to anaoshak
    Level 7 (24,115 points)
    Safari
    May 12, 2015 5:33 AM in response to anaoshak

    1. Your iMac5K is an UEFI compliant machine and should be the fastest using that method. For such machines, using BC Assistant does not really add much value. These can directly boot from the Installer when using EFI Boot.

     

    2. Bootcamp Assistant has bugs when it comes to EFI boot. It seems to be inconsistent in picking the EFI method despite knowing the iMac model and its internal list of UEFI models from the Info.plist .

      <key>PreUEFIModels</key>

            <array>

                    <string>MacBook7</string>

                    <string>MacBookAir5</string>

                    <string>MacBookPro10</string>

                    <string>MacPro5</string>

                    <string>Macmini6</string>

                    <string>iMac13</string>

            </array>

     

    3. Using Bootcamp Assistant on Fusion drives has additional caveats. It forces the user to use the slower HDD than the faster SSD. This is more of a safeguard mechanism used by BCA. If the user requests a Windows partition larger than the SSD, there is no logic in BCA to do this. BC Engineers choose the simpler model of partitioning a Fusion drive. I would have preferred two choices.

         a. Use the SSD but limit it to half the size of SSD. If user requests more than that then let the user know they will get a slower partition on the HDD only.

         b. Let the user pick the underlying physical disk where they want Windows, provided the conditions in item a. are met.

         c. This requires additional logic, which can become overly complex, a model the Steve Job's Apple DNA will not permit.

  • by anaoshak,

    anaoshak anaoshak May 12, 2015 5:41 AM in response to Loner T
    Level 1 (6 points)
    Windows Software
    May 12, 2015 5:41 AM in response to Loner T

    Will having  a larger Windows Partition make my OS X partition slower?

    So theres no way I can resize my windows partition to be larger?

     

    I guess one of my questions was confusing that I asked earlier. If I don't want the windows partition anymore, do I goto BCA and just remove the partition like most people would?

  • by Loner T,

    Loner T Loner T May 12, 2015 5:48 AM in response to anaoshak
    Level 7 (24,115 points)
    Safari
    May 12, 2015 5:48 AM in response to anaoshak

    No. The two OSes are self-contained. They share the same hardware. By design, OS X is on SSD and has a Fusion drive defined, so it will stay quick. The primary issue is Windows. In my specific case, I chose to move my Windows installation, and I use a larger SSD (256G/512G) compared to what Apple provides (120G). BIOS method disallows changing the size of the partition because it uses a MBR. They must stay in sync for both OSes to function properly.

     

    BCA should be the only tool used to remove Windows which was installed using BCA. It does a lot more than just removing Windows. For example, it merges the disk space used by Windows back into the main OS X partition. It also cleans up the MBR.

  • by anaoshak,

    anaoshak anaoshak May 12, 2015 5:49 AM in response to Loner T
    Level 1 (6 points)
    Windows Software
    May 12, 2015 5:49 AM in response to Loner T

    I see. Last question, if I was to remove the Windows partition, what method would I use?

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